Production of sheets and plates of manganese steel.



WINFIELD S. POTTER, OF NEW YORK, N. Y.

raonucrron or SHEETS AND PLATES or Menom nee srnnn.

No Drawing.

Specification of Letters latent.

To all whom it may concern:

Be it known that I, W'mrmno S; PorrER, a citizen of the United States, residin in New York city, county and State of ew York, have invented certain new and useful Improvements in the Production of Sheets and Plates of Manganese Steel; and I do hereby 'declare the following to be .a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

Myinvention relates to the rolling of sheets or plates from manganese steel billets or blanks, (having a percentage of manganese above 51} per cent. and usually containing about 12 percent.) and has for its object to produce a final product of a substantially uniform fine-grained condition throughout, and having the desired stiffness or ductility appropriate to the use for which it is intende I In carrying-out my invention, I first-heat the manganese steel billet or sheet bar until it is brought into a uniform and ductile condition throughout, appropriate-to the rolling operation. To this end, the necessary plasticity is imparted to the billet or sheet bar by raising it to atemperature which, for the production of the best results, will usually be above the melting point of the eutectic alloy, 2'. (2., above 1125 C. (say,

1125 C. to 1225 (3., according to the ductilit-y required .for rolling), but which, in some instances,-may be aslow as say 1060 C. provided the subsequent reduction from the billet to the sheet or plate in a single heat is not considerable. The blank is then rolled to the desired dimensions, orreheated and further rolled to gage, and if it then has a temperature above 800 C. and below 107 5 C. it may be immediately quenched with the production of a product having a stiffness or ductility corresponding to the percentage of reduction and to the finishing temperature. a

When the sheet cannot be finished with the intended dimensions and with the desired temperature for quenching, the rolling operation is continued until the blank has been reduced to almost its final dimensions. The rolling is then interrupted and the resulting blank is placed in a heating furnace and is therein brought to a temperature which is equalized throughout and which is sufficient to permit the continuation of the rolling operation withthe delivery of the product from the ultimate finishing pass of the rolls at a temperature between 800 C. and 1075 C. The higher temperature is preferred when greater ductility and soft ness are desired in the finished sheet orvplate,

and a lower temperature, as, for example, a temperature between 800 C. and 900 C.

is preferred, when greater stiffness aud t;

higher elastic limit in the finished product are required. At the termination of the rolling operation and preferably as soon as Patented Feb. 20, 1912.

Application filed November 3, 1911. Serial No. 658.425.

possible after it has issued from the last I pass in the rolls, the finished sheet or plate' is cooled or quenched so as to preservethe qualities due to the rolling operation as determined by the finishing temperature, together with the effects of the initial heating, which in all cases is assumed to have been such as would bring the blank to a condition of uniform solution of the constituents of the metal. After the quenching operation, the sheet may be cold rolled, which has the effect of further stiffening it and of affording smooth surfaces.

Where a lesser stiffness is required, this quality of product can be obtained b suitably reheating and quenching, and't e finished sheet may be delivered to the reheating furnace direct from the roliing oper;-'

ation, is held therein for 'a short time at about the finishing temperature (say at 800 G. to 1025 C.) and is then quenched.

In the reheating operation immediately preceding the final rolling to finished ga e and dimensions and particularly when in t e final intended rollin operation, the percentage of reduction an the attendant compression, working and grain breakage are not sufficient alone to secure the desired hardness or stiffness, the temperature in the reheating operation should not be such nor the time of heating so longas to destroy the effects of the preceding rolling and working. In such cases, the temperature for the reheating furnace should not be much, if any, above 10''? 5 (1, nor the time during which the sheet remains in the reheating furnace more than say 12 minutes for fl; inch of thickness, or such time as will bring the blank to the furn'ace temperature throughout. Indeed, a safer limit for the temperature of the reheating operation is about 1025 C.

A tough sheet or plate of moderate stiffness may be produced by heating the blank in a temperature suitable for the required etanple, 1200 U, s and pie, 1000" 0., int; so to avoid ition, subsequently U, for example as and immediately R I w;

wrought con to abeut 3.00s

described,

on n e A Haw" thus described my inventiomwhat he method of making sheets or plates manganesesteel, which comprises heating a. billet or? blank oi" manganese steel until in a uniform ductile condition throughout,

low

making shee r plates which compr' heating 7 1 manganese steel until. in. ,d tltLC ile condition tliri'n'ighout,

" working, the temperi the worki n and thereby working, the temper diate ireheating, the temperature at finishing 45 of the working being below l075 (1 and quenching, the quenching being preceded by reheating at about the finishing temperature, for such time only that the sheet or plate is suitably annealed or toughened;

substantially as described.

The method oi? making sheets or plates of manganese steel, which comprises heating a billet or' blank of manganese steel until in a uniform and ductile condition throughout, rolling .v diate reheating, the temperatures at finishing of the working being below 1075 (l, and quenching; substantially as described.

6. The method of making sheets or plates of manganese steel, which comprises heating a billet or blank or manganese steel until in a uniform and ductile condition throughout, rolling and thereby working, with interme diate reheating to a temperature not above 1075 Q, the temperature at finishing the rolling being below 1075 C, and quenching, substantially as described.

in testimony whereof I affix my signature, in presence or" two witnesses,

WINFIELD S PQTTER,

i tnesses 2 dorm C Pnianm, Minimum LOBEL,

eby working, with internae 

